Adjustable threaded connection



Jly 16, 1946. J, W, LElGHTON 2,404,076

` i ADJUSTABLE THBEADED CONNECTION Filed May 4, 1944 W2 9 fly@ yare required at the ends of the arms.

Patented July 16, 1946 UNITED STATES PATENT OFFICE 1 claim. l

The invention relates to pivotal connections and it has particular relation to pivotal connections for use in automobile wheel suspensions.

In individual suspensions, the Wheel is connected to the vehicle frame by means of linkage having arms and accordingly pivotal connections It has been general practice in the manufacture of motor vehicles where individual wheel suspensions are used to employ threaded bearings so that the pivotal or oscillatory movements occur on the surface of threads. In most instances, a threaded bushing is employed between the two parts pivotally connected and in certain cases the bushings have been adjustable in order to permit camber or caster variations.

One object of the present invention is to provide an improved pivotal and threaded bearing which permits ready adjustments in order to take up clearances between threads such as may Occur on account of wear during use of the bearing.

Another object of the invention is to provide a bearing of this character which may be easily manufactured and assembled so that the cost thereof may be maintained at a minimum.

Another object f the invention is to provide pivotal connections such as indicated which are particularly applicable in connection with substantially spaced threaded bearings as employed in connection with that type of suspension having the linkage directed longitudinally of the vehicle and wherein lateral stability must be Obtained at least partly through the substantialll7 long pivotal connection.

Other objects of the invention will become apparent from the following description, from the drawing to which it relates and from the claim hereinafter set forth.

For a better understanding of( the invention reference may be had to the accompanying drawing wherein:

Figure l is a cross sectional view illustrating a pivotal connection constructed according to one form of the invention and which is employed in connection with two arms or links extending laterally from the vehicle frame;

Figure 2 is a cross sectional view illustrating application of the invention to a pivotal connection between a. single arm extending laterally from the vehicle frame and a vertical wheel supporting member;

Figure 3 is a cross sectional view illustrating use of one form of the invention in connection with a link forming part of an individual wheel suspension which extends longitudinally of the vehicle frame;

Figure 4 is a cross sectional View taken substantially along the line 4 4 of Figure 3.

Referring to Figure 1, the construction illustrated includes a pair of links or arms IE) and I I extending laterally from the vehicle frame and having their inner ends pivotally connected thereto for up and down swinging movement about a horizontal axis extending longitudinally of the frame. 'I'hese arms respectively at their outer ends have extruded portions I2 and I3 which are provided with threaded openings I4 and I5 located in aligned relation. A threaded pin I 'I is threaded through both of the openings I4 and I5 and at one end has a hexagonal head I8 engaging one arm and at its other end a nut I9 engaging the other arm. Lock washers or other suitable locking means may be employed for holding the nut I9 in position and in normal use the pin does not turn but remains fixed to the arms.

A wheel mounting member is indicated at 2i and this member extends vertically between the outer ends of the arms I0 and II and another arm or arms also extending laterally from the vehicle frame but disposed in vertically spaced relation to the arms I0 and Il. In this connecn tion, it may be said that the arms IIJ and I I may be at the lower part of the suspension so that they may be connected to the lower part of the mounting member 2I, while a single upper arm may be connected to the upper end of the wheel mounting member in the manner presently to be explained in connection with Figure 2.

The upper end of the mounting member 2| has a solid portion 23 provided with an internally threaded opening 24 and a bifurcated portion 25 separated from the upper half of the solid portion by a slot 22 extending half way through the Opening has a cylindrical, non-threaded portion 26 aligned with the threaded opening 24. Both of these openings are substantially larger than the threaded pin I'I and the latter projects through them.v In order to provide a pivotal connection between the threaded pin and the member 2l, a bushing 23 having a head 29 and a body portion 38 is threaded into the opening 24 until the head 29 engages the side of the portion 23 of the member. The threads on the bodv 30 and in the opening 2t are of shallow7 obtuse angle character so that when the bushing is threaded into the opening and the head 29 is drawnup tightly against the mounting member, the thread surfaces on the two parts become locked tightly together through a wedging ac- 3 tion. Hence, the bushing 29 is locked` rigidli7 to the wheel mounting member.

Internally, the bushing 29 is provided with normal threads 3| which engage the threads on the pin l1. This threaded engagement permits free relative turning of the bushing and wheel mounting member with respect to the pin I1, or, in other words, the bushing and pin have a threaded bearing engagement.

The bifurcated part of the wheel mounting member receives a bushing 34 having a body portion 35 slidable in the cylindrical opening 26 and a hexagonal head portion 36 which facilitates turning of the bushing when desired. This bushing has internal threads 31 engaging the threads on the pin I1 so as to provide a threaded bearing engagement such as previously mentioned. Externally, the body 35 has an annular groove 39 which has a cylindrical bottom d. For locking the bushing 34 to the wheel mounting member in any position of adjustment, a clamping bolt 42 is provided and this bolt extends through openings in the ends of the bifurcated portion 25. The bolt may be on the order of that shown by Figure 4 and has a head on one end and a nut on the other so as to draw the two ends of the bifurcated portion together in such manner as to tightly clamp the bifurcated portion about the body portion of the bushing.

The clamping bolt extends through the groove 4i) and accordingly when the bolt is in place the bushing can be moved axially only within limits depending upon the axial length of the groove. It follows that the bushing 34 may be adjusted axially within limits when the bolt is loosened and that the bushing cannot be moved beyond certain limits with the bolt in place.

In the event the threaded engagement between the two bushings and the pin becomes undesirably loose owing to wear, or if there is too much clearance at any time such as when the parts are initially assembled, the play can be effectively eliminated by turning the bushing 34 after the bolt 42 has been loosened. When the bushing 3:5

is in abutment with the end of the bushing 2S a any further turning of the bushing 34 relative to the bushing 28 will shift the pin relative to the bushings so that play in the threads can be reduced or eliminated. All of the play might be eliminated in this manner or the play might be f partly eliminated as may be found most desirable.. After the bushing 3a is adjusted to the desired extent, the bolt 42 is again tightened so as to lock the bushing 3d in place and then both bushings become rigidly held in the openings of the wheel mounting member and turn therewith relative to the pin during operation of the joint.

Sealing members 45 and l5 may be disposed at opposite ends of the pivo-tal connection between the bushings and the arms respectively so as to prevent dirt or other foreign matter from gaining access to the threaded bearing. At the same time, the sealing elements prevent the escape of lubricant. For lubricating the bearing, the pin may have an axial opening 41 leading to one end and a grease fitting may be placed on such end of the pin as will be readily understood. A radial opening d8 leading from the opening 41 to the external surface of the pin allows the lubricant to now to the threads.

In the arrangement shown by Figure 2, the wheel mounting member 2| at its upper end has bushings 553 and 5i which correspond to the bushings 28 and 3d except for certain distinctions which will be Clear hereafter.

Similarly to the structure shown by Figure 1, the upper end of the wheel mounting member has a solid portion 53 and a bifurcated portion 54 cooperating with the bushings in the manner previously stated. Instead of using a pin in this case, the upper arm of the wheel suspension is in the form of a rod 54 extending laterally from the Vehicle frame and having an offset or bent portion 55 extending longitudinally of the frame. This longitudinal portion 55 is externally threaded and extends through both of the bushings.

For lubricating the bearing, the end of the bushing 5i), has a welch plug 56 therein and this plug has a central threaded opening 51 adapted to receive a grease fitting. Lubricant is prevented from escaping at the end of the other bushing by a resilient sealing ring 53 seated on the end of the trunnion and against a shoulder 59 and which has a rim portion '6D annularly embracing a cylindrical end portion 6l of the bushing,

It might be observed that the position of the lower end of the member 2| may be varied longitudinally of the vehicle by locating it at the desired point between the arms l@ and il prior to threading the pin l1 into place and through the threaded openings. Likewise, the position of the upper end of the arm 2l may be shifted along the vehicle by threading the end of the trunnion to a greater or lesser extent through the bushings during initial assembly. Depending on initial play in the threads or clearances, the wheel mounting member 2l might be tilted with respect to the vertical a slight amount for caster adjustment purposes and after positioning the member for this purpose, the bushings 34 and 5| may be tightened against the bushings 28 and 53 so as to remove additional play in the threaded bearings if desired. At any time during use, the threading bearings may be adjusted as previously stated so that the desired play in the bearings can be maintained.

In the arrangement shown by Figure 3, a wheel mounting arm ('35 is provided which extends longitudinally of the vehicle frame shown partly at 56. This wheel mounting arm, at its forward end, not shown, is connected to a wheel and normally an upper and a lower arm will be ernployed. At its rear end the arm has an opening 61 which receives a pin {it} and for holding the arm in position, a nut 69 is threaded on the end of the pin. For locking the arm and pin together, the pin may have a keyway or it may be serrated so that turning of the arm causes turning of the pin.

The pin extends through a sleeve or tubular member 'it fastened on the frame member 65 and. beyond the opposite end of the tubular member, a shock absorber arm 12 is secured to the pin by means of a nut 13. Within the tubular member the pin has a larger threaded portion 15 and a smaller threaded portion 13 and these threaded portions are substantially smaller than the tubular member. A bushing 11 is threaded into the outer end of the tubular member 1Q and the threaded engagement is of the obtuse angle n A similar bushing 82 is disposed in the other end of the tubular member and is threaded on the pin portion 16 but this bushing has a cylindrical outer surface 83. A head 84 on the bushing facilitates turning it. For clamping the bushing 82 in position in the tubular member, the end of the latter has four circumferentially spaced slots 85, 86, 81 and 88 and around this slotted end portion, a clamping member 90, shown best by Figure 4, is provided. This clamping member has a portion projecting into the slot 86 to locate the member circumferentially and also has ends 9| and 92 which are apertured and receive a clamping bolt 93 having a head 94 on one end and a nut 95 on the other. When the bolt is tightened, the segments between the slots are contracted so as to tightly clamp the bushing 82 and lock it positively to the tubular member.

A grease tting may be applied to the tubular member 'I0 at any point between the bushings so as to provide lubricant and rubber sealing elements 96 and 91 at opposite ends of the bushings may be provided to prevent the escape of lubricant. A torsion spring 98 is shown also and this is connected at one end to the arm 65 and at its other to the frame.

In assembling the parts, the bushings 19 and 82 may be placed in position in the member 'IIJ and then the pin may be inserted from the outer or left end of the member. The diameter of the threaded portion 1B is such as to allow its passage through the bushing 11 and when the pin has been moved inwardly suiciently the threads 15 will engage the threads in the bushing 11 and then the pin is advanced by turning it. As soon as the threads 16 on the pin reach the threaded engagement occurs.

threads in the bushing 82, they will thread into the second bushing providing the threads are properly disposed, but since the bushing 84 is adjustable, it may be moved or adjusted until After the pin is in place, undesirable play in the threads may be removed by turning the bushing 83 after its head 84 engages the end of the tube and then any further turning of the bushing will require axial shifting of the pin. When the thread engagement has been adjusted to the desired extent, the clamping bolt 93 is tightened so as to lock the bushing 82 in position.

Although more than one form of the invention has been illustrated and described in detail, it will be apparent to those skilled in the art that various modifications may be made without departing from the scope of the appended claim.

What is claimed is:

A pivotal connection comprising a tubular element, a bushing threaded into and fixed in one end portion of the element and being internally threaded, a second internally threaded bushing having an internal diameter smaller than that of the first bushing and being axially slidable in the other end portion of the element, the latter portion being axially slotted, a shaft or trunnion element extending through the tubular element and having larger and smaller threaded portions engaging the threads of the bushings respectively, the smaller portion being bodily movable through the larger bushing opening without threading it therethrough, means for clamping the slotted end of the tubular element about the bushing therein, and a member connected to one end of the shaft so as to turn therewith.

JOHN W. LEIGHTON. 

